Tiny freshwater creature, first found in Southern Ontario, is understudied and likely endangered 0

The freshwater mussel with the evocative name is all but gone from Ontario waters, almost before we knew it even existed.

The first live lilliput in Canada was found and identified in the Sydenham River in 1991. Just 47 others have been found since, all in little pockets of little rivers in Southern Ontario.

Now the country’s Fisheries and Oceans Department is looking to designate the rarer-than-rare creature an endangered species.

“It’s either a very hard mussel to find or it’s a very rare mussel,” said John Schwindt an aquatic biologist with the Upper Thames River Conservation Authority.

“They’re really under-studied and under-inventoried.”

The lilliput mussel is as tiny as its whimsical name would suggest— the moniker inspired by the fictional little island people in Gulliver’s Travels — and about the size of an adult’s thumb.

It’s native to North America and is found, although rarely now, in parts of the U.S. Midwest. Eight pockets of Southern Ontario are its only known Canadian habitat.

The Fisheries and Oceans Department is seeking public comment until Sept. 15 on its plan to designate and protect what few living lilliputs might remain.

Mussels are nature’s water filters and the presence or absence of different species is one barometer of a river’s health, Schwindt said. They’re particularly sensitive to pollution or to competition from invaders such as zebra mussels.

“Species like the lilliput are so small we don’t really know what its specific role is,” Schwindt said, but that doesn’t mean it’s insignificant.

“Going back to Biology 101, a diverse system is a hardier, healthier one.”

A freshwater mussel that’s about 5-cm long, with a dark brown elliptical or oval shell. Host fish swallow their larvae, which then attach themselves to host fish’s gills before maturing enough to settle in riverbeds.

In Canada, found only in Ontario.

Lilliput shells first discovered in Ontario in 1913. First live lilliput found in Sydenham River in 1991.

Remaining habitat believed to include deep water bed of Sydenham River, Lower Thames River (Baptiste Creek) as well as some sites near Hamilton and Welland.

Federal protection under the Species at Risk Act would mean any work around its habitat (bridge-building or dredging, for example) would first require a search for lilliput. It would be illegal to kill, harm or capture the mussels or destroy its habitat.